title: Circadian rhythm of interleukin-1 production of monocytes and the influence of endogenous and exogenous glucocorticoids in man.
abstract: We found a dose-dependent inhibition of spontaneous and LPS-induced IL-1 production of isolated human monocytes by methylprednisolone (MP) in vitro. Kinetic studies of spontaneous and LPS-induced IL-1 production of isolated monocytes of 10 normal individuals showed a synchronous circadian rhythm, with its maximum at 4:00 p.m. and its minimum at 4:00 a.m., which is most probably independent of the physiological circadian rhythm of cortisol levels because the IL-1 production was of the same value at the times of maximum and minimum cortisol levels. In contrast, in a patient with hypercortisolism and a preserved circadian rhythm of cortisol levels, we found the minimum of IL-1 production at 4:00 p.m., 8 hours after the maximum cortisol level was reached. Furthermore, in 7 patients with sarcoidosis both spontaneous and LPS-induced IL-1 production of isolated monocytes were significantly decreased 8 hours after the first injection of MP (1 mg/kg bw i.v.) compared to the values before MP administration. Our findings suggest a physiological circadian rhythm of spontaneous and LPS-induced IL-1 production of monocytes, independent of physiological cortisol levels, whereas unphysiological amounts of endogenous and exogenous glucocorticoids cause a substantial inhibition of IL-1 production with a latency time of 8 hours.
authors.affiliation: Medizinische Klinik, Forschungsinstitut Borstel.
authors.forename: P
authors.initials: P
authors.lastname: Zabel
authors.forename: H J
authors.initials: HJ
authors.lastname: Horst
authors.forename: C
authors.initials: C
authors.lastname: Kreiker
authors.forename: M
authors.initials: M
authors.lastname: Schlaak
mesh_terms: D000328:Adult; D002478:Cells, Cultured; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008775:Methylprednisolone / Q000494:pharmacology*; D009000:Monocytes / Q000378:metabolism*; D012507:Sarcoidosis / Q000378:metabolism
chemical_list: D007375:Interleukin-1; D008070:Lipopolysaccharides; D006854:Hydrocortisone; D008775:Methylprednisolone